The objective of the proposed research is to characterize the mechanism of actin-dependent pigment granule motility in RPE cells of teleosts. A model proposing that centripetal aggregation of pigment granules is linked to centripetal flow of actin filaments while centrifugal dispersion of pigment granules is affected along actin filaments via myosin motors, will be tested. Specific aims are to 1) characterize the ultrastuctural organization of F actin in RPE cells, 2) determine the polarity of actin filaments in RPE apical projections via S1 labeling, 3) determine whether particles attached to the surface of RPE cells undergo centripetal transport and 4) localize myosins VI and VIIa in RPE cells.